Age-related Facilitation of Bimanual Finger Behaviors by Haptic Augmentation

Proficient use of multiple fingers across both hands enables complex interactions with the world. Developing dexterity for delicate bimanual tasks can take weeks to years to master. This study examines whether a simple mechanical abstraction can enhance bimanual response times to visual stimuli using index fingers and thumbs. A plate placed over the buttons was introduced to shift task conceptualization—rather than pressing buttons, subjects rocked the plate over them. Following this mechanical augmentation, we observed improved bimanual performance in middle-aged participants but no effect on unimanual actions. Conversely, younger adults showed no performance improvement. A control group of middle-aged participants confirmed that the observed improvements resulted from the augmentation. We hypothesize that highly similar afferent sensory signals from the fingers of both hands alter the motor control strategy. This work provides a foundation for further research into the diverse mechanisms of multi-fingered bimanual behavior in both abstract and practical contexts.